The A380 is far from being a type rating that will not get you a job elsewhere. The whole Airbus family from from the A318 to the A380 are incredibly similar to operate hence the ability for MFF. If an A380 pilot wants to convert to the A320 the course is a matter of days.
There will be plenty of jobs advertised when the A350 comes along that will state "Airbus wide body experience required".
In my opinion the A380 is a far more useful type rating to have for these very reasons.